We have established conditions for the large scale purification of plasma membranes from the guinea pig L2C leukemia. These purified plasma membranes will be solubilized with detergents and individual protein and glycoprotein components will be isolated with a view to studying their structure, biosynthesis and function. We will also purify plasma membranes from normal guinea pig lymphocytes to identify differences between these and the leukemia membranes. Our major interests are the tumor specific antigen, the Ia antigen, and the blood group i antigen. BIBLIGRAPHIC REFERENCES: Cooper. A.G. and Brown, M.C. "Automated Hemagglutination Inhibition." Chapter 20 in Automated Immunoanaylsis, Ritchis, R.E. Editor, Marcel Dekker, New York 1977, in press. Katki, A.G., Cooper, A.G. and Wallach, D.F.H. "Some functional properties of the mitochondria from leukemic (L2C) guinea pig lymphocytes. Proc. Amer. Assoc. Cancer Research 18, Abstract No. 197, 1977.